Solved Z Axis Motor(s) problem

My prints have perfect quality when printing on the X and Y axis but when the Z axis is being used, there's a weird click when it turns past a certain point. I can't figure out how to fix it since I've only just got this printer (used). I wouldn't mind buying another motor but I would prefer that I can fix it.

Additional info: This clicking makes my prints walls completely weak and liable to break just from removing it from the print bed due to raising it slightly with each jump. It also causes the prints to be extremely bigger than they are Z-axis wise. I made a fan holder that was supposed to be just over 1 inch on Z, but after the print finished, it came out at almost 2 1/2 inches on Z.

 

Are you perhaps running the r1+ firmware by mistake?

 

It's on ROBO3DR1V3, not sure what firmware is supposed to be on it or even fully sure if it's a plus model. Is there some way I can check and make sure it's an R1+ like the seller said? It came with a heated bed and E3D V6 Hotend.

 

He added the hotend, it does have couplers (the round thing at the base of the Z's?) and no quick release as far as I can tell.

 

That sucks, then is my firmware correct? I already ordered replacement motors, just in case. When printing it's fine at first then after a while it start clicking again

 

I'm gonna try to replace the fan at the bottom. I reached under there and I can't really feel it.

 

OMG, turns out the fan at the bottom wasn't wired correctly. I didn't know what I was doing and when I went to check on it being on while the power was on, it was never on since I didn't match the correct polarities. I feel like an airhead. I never turned it on and had the bottom up for me to see since I was scared I'd mess something up. Printed out a cable holder and it came out just short of perfect. Gonna do more test prints and see if it works now.

 

Printed out 4 feet one at a time for my R3D while I was at work, came out flawless. Big thanks to everyone and @WheresWaldo for figuring out what the problem was!